SU1302253A1 - Device for stabilizing a.c.voltage - Google Patents

Abstract

The invention relates to secondary power sources of radio equipment. The aim of the invention is to increase the reliability of a device for stabilizing an alternating voltage by eliminating high voltage surges in a booster transformer. The instantaneous value of the output voltage at the load 11 is determined by the sum of the instantaneous values of the mains voltage and the EMF of the secondary winding 9 of the booster transformer 4. When the mains voltage changes, the duration of the on state of the thyristor 6 changes inversely proportional to the duration of the on state of the thyristor 7. 1 Il. from o to to ate oo

Description

The invention relates to electrical engineering, in particular to semiconductor voltage regulators, and can be used, for example, to power lighting installations.

The aim of the invention is to increase the reliability of an alternating voltage stabilization device by eliminating high voltage surges in the booster transformer.

The drawing shows an electrical circuit of a device for stabilizing a variable voltage.

The alternating voltage stabilizer contains an input terminal 1, a common bus 2, an output terminal 3 and a booster channel, made in the form of booster transformers 4 and 5, controlled thyristor switches 6 and 7, and a block 8 for controlling thyristor switches. The secondary windings 9 and 10 of the boost transformers 4 and 5 are interconnected to each other and connected in series with the lighting load 11 connected to the output terminal 3 and the common bus 2 of the device. The primary windings 12 and 13 of booster transformers 4 and 5 are connected to the input terminal 1 and the common bus 2 of the device and are connected in series with each other, and the thyristor switch b is connected parallel to the winding 12, and the thyristor switch 7 is connected parallel to the winding 13.

The device for stabilizing the alternating voltage operates as follows.

At the beginning of the positive half-cycle of the mains voltage (the direction of the load current III) with the closed thyristor switch 7, the control unit 8 is supplied with a triggering pulse to the thyristor switch 6, which, opening, short-circuits the primary winding 12 of the booster transformer 4 and simultaneously supplies the supply voltage to the primary winding 13 booster transformer 5. Current direction 1 | and b for this time variable is shown in solid lines. The current flowing through the tHpHCTOpHb key 6 is determined by the sum of the currents i and b. The instantaneous value of the output voltage at the load 11 is determined by the difference of the instantaneous values of the network voltage and the EMF of the secondary winding 10 of the booster transformer 5. At the time determined by the output voltage, a control pulse is supplied from the control unit 8 to the thyristor switch 7, which open, shorting the primary winding 13 of booster transformer 5. The directions of the currents P. Ii and b for this point in time are shown by dashed lines. The component of the current if through the thyristor switch 6 is directed opposite to the direction of the current, the current quickly decreases

0

5 5

0

shifts to zero and the thyristor switch 6 is closed.

A mains voltage is applied to the primary winding 12 of booster transformer 4 and the current flowing through the thyristor switch 7 is determined by the sum of the currents 1, b. The instantaneous value of the output voltage at the load 11 is determined by the sum of the instantaneous values of the network voltage and the EMF of the secondary winding 9 of the booster transformer. 4. At the end of the positive half-cycle of the mains voltage, the current through the thyristor switch 7 is reduced to zero and the switch 7 is closed. In the negative half-period of the mains voltage, the thyristor switches 6 and 7 work in a similar way. When the mains voltage decreases, the duration of the on state of the thyristor switch 6 decreases, and the thyristor switch 7 increases accordingly. As the mains voltage increases, the turn-on time of the thyristor switch 6 increases, and the thyristor switch 7 decreases accordingly.

Thus, the proposed device for stabilizing an alternating voltage provides a continuous stabilization of the output voltage at the load with deviations of the mains voltage from the nominal value not exceeding the EMF values of the secondary windings 9 and 10 of booster transformers 4 and 5.

Claims (1)

Invention Formula An alternating voltage stabilizing device containing the first voltaic-transformer transformer, the end of the secondary winding of which is connected to the input terminal, two thyristor switches, the first power terminals of which are interconnected, the second power output of the first thyristor switch connected to the beginning of the primary winding of the first booster transformer , and a control unit, inputs connected between the output terminal and the common bus, and outputs connected to the control terminals of the thyristor switches, characterized in that To improve reliability by eliminating high voltage surges in the booster transformer, a second booster transformer was inserted into it, with the end of its secondary winding connected to the output terminal and the beginning connected to the beginning of the secondary winding of the first booster transformer, the end and the beginning of the primary winding booster transformers are interconnected and connected to a common point of thyristor switches, the end of the primary winding of the second booster transformer. estno with the second power terminal of the second 1302253 34 the thyristor switch is connected to the common mater and the second power output of the first bus; the common point of the beginning of the primary thyristor switch is connected to the input coil of the first booster transformer terminal.